Overview

Raising your core body temperature is called hyperthermia. It can harm your developing baby (fetus). It's most harmful during the early weeks when the organs are forming. Experts don't forbid hot tub or sauna use. But they do advise caution.^{footnote 1}

Hyperthermia during the first weeks of pregnancy has been linked to neural tube defects.^{footnote 2} So pregnant women are advised to treat a high fever with acetaminophen. They should also avoid other causes of hyperthermia.

If you use a hot tub or sauna, be careful. The tub or sauna should not be so hot that you are uncomfortable. And limit how long you sit in the hot tub or sauna. Experts suggest using a sauna for no more than 15 minutes and using a hot tub for no more than 10 minutes. To help keep from getting too warm in a hot tub, sit with your arms and chest above the water.^{footnote 1}